Flower 1.2.0 / 2.0.1 error on Tornado

[MBTRabadon]

I was using flower==1.2.0 and no issue encountered since last week in our dev environment. I also don't have tornado in the requirements.txt. After accessing yesterday, with no redeployment and no change, it has an error suddenly:

KeyError: '_tt_execute'
  File \"/usr/local/lib/python3.9/site-packages/tornado/web.py\", line 1848, in _execute\n    result = await result\n
  File "/usr/local/lib/python3.9/site-packages/flower/views/workers.py", line 72, in get
    self.render("workers.html", ...)
  File \"/usr/local/lib/python3.9/site-packages/flower/views/__init__.py\", line 36, in render\n    super().render(*args, **kwargs)\n
  File \"/usr/local/lib/python3.9/site-packages/tornado/web.py\", line 1143, in render_string\n    return t.generate(**namespace)\n
   File \"/usr/local/lib/python3.9/site-packages/tornado/template.py\", line 357, in generate\n    execute = typing.cast(Callable[[], bytes], namespace[\"_tt_execute\"])\n

Despite installing flower==2.0.1 (either via PyPI or directly from GitHub), the error still occurs. This is running using command:

docker compose up flower

I changed versions to
tornado==6.3.3,flower==2.0.1
tornado==6.1.0,flower==1.2.0

but still encounter the errors. i also updated the celery version. Please help.

I have a Dockerfile to build

# pull official base image
FROM python:3.9

# set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1

# Install nodejs for translators library
RUN apt-get install -y nodejs

# set work directory
RUN mkdir /backend/
WORKDIR /backend/

# install dependencies
RUN pip install --upgrade pip
COPY ./requirements.txt .
RUN pip install -r requirements.txt

# Set environment variables
ENV CELERY_WORKER_AUTORELOAD=False

# celery configurations
COPY ./start-celeryworker /start-celeryworker
RUN sed -i 's/\r$//g' /start-celeryworker
RUN chmod +x /start-celeryworker

COPY ./start-celerybeat /start-celerybeat
RUN sed -i 's/\r$//g' /start-celerybeat
RUN chmod +x /start-celerybeat

COPY ./start-flower /start-flower
RUN sed -i 's/\r$//g' /start-flower
RUN chmod +x /start-flower

# copy our django project
COPY .. /backend/